61 karma · joined December 19, 2009
It's true that FP is presented too often as a remedy for the common ailment of programming of not producing software that you can understand quickly enough. Also known as 'productivity'. But just because it's over-enthusiastically promoted it doesn't mean there's no truth to the claims. It's mostly that
a. you can compose your software nicely from parameterizable operations over common structures (map, reduce, filter, take, etc.)
b. mutable state can make programs messy so you should avoid it
But of course you don't care. At all. After all, if you did, you wouldn't be quickly hand waiving the whole issue with a fleeting reference to 'recursion', as if it was the dominant instrument in functional programming. You learn _very_ early that writing recursive functions is just more work than throwing together a bunch of functions over a sequence or some such if needed.Well, I must say that I haven't seen any other application of its size take the "NO WARRANTY" shouting of the GPL so seriously.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
But the program did start as a showcase for some graphics manipulation algorithms that the authors made. Maybe the fault is with the people with the high hopes that it was actually meant for them to use and edit their photos.If anything, C has a much more academic pedigree, being born in an industrial research lab and having /gasp/ an specification.
Also, you generalized the principle (and fused two exercises of the book in one :), or at least I'll have to believe you ;) I didn't form really much of an intuition on eigenvectors during the completely proper Linear Algebra course that I took, which is only my fault.
But I think that the exercise serves to reinforce the underlying theme that with enough attention, one can either supply or draw the insight to chip away yet one more part of the problem, to attack it from another angle, to pull it from just another direction that one had not seen before. It celebrates cleverness and knowledge, used to make complex things simple, to find the easy way out the hard way and end up better in the end, and that's partly why it's so cherished, but we all know that.
Yes, that's very true, but it's also a red herring. Not all code is worth to read, nor is it worth to write. Certainly not either the copy+pasted mess that would result of not using first-class functions, or all the _noise_ introduced by their half assed expression using classes.
> The other point IMHO is that scattering your code with anonymous functions points to bad design and is as bad as scattering "GOTO" everywhere in BASIC code. It leads to spaghetti code which is an unmaintainable mess.
Spaghetti? Really? As in flow of control? You _really_ don't know what you are talking about. Sure, it does enable some trickery, like Continuation Passing Style, but if you are arguing that such a technique is a 'con' for the existence of what amounts to just both functions and lexical scope, you are grasping straws.
On the other hand, you have simple abstractions that are enabled by first-class functions, like map or the folds, and you won't have to hear of silliness like the 'Command Pattern' or the 'Strategy Pattern' to work around the restrictions that make them necessary. And the subsequent explosion in code, to be found later shoved in other classes and packages. They make dispatch tables easy, they give you a simple way to make asynchronous code, they allow wrappers for guarded code, they...
Do yourself a favour and take a good look to the first two chapters of SICP (http://mitpress.mit.edu/sicp/), most of their charm is displayed there.
Actually, let's not. To paraphrase a minor celebrity of programming, life is too long to be good at reading every variation of boilerplate. Java is essentially hostile to small functions and parametrization, as having any semblance of inner or anonymous functions will require you to define a class at least, or an interface somewhere else, scattering your code unnecessarily, and you'll probably just end up repeating the code because it's just not worth the effort to do it. Don't believe me? Why do you always have to .open() and .close() your any port-like thing manually? That's a solved problem, you know?